Deep neuromuscular blockade during spinal surgery reduces intra-operative blood loss: A randomised clinical trial

A survey of practice in the anesthetic management of adolescent idiopathic scoliosis spine fusion by the North American Pediatric Spine Anesthesiologists Collaborative

BACKGROUND

Adolescent Idiopathic Scoliosis (AIS) affects 2%-4% of the general pediatric population. While surgical correction remains one of the most common orthopedic procedures performed in pediatrics, limited consensus exists on the perioperative anesthetic management.

AIMS

To examine the current state of anesthetic management of typical AIS spine fusions at institutions which have a dedicated pediatric orthopedic spine surgeon.

METHODS

A web-based survey was sent to all members of the North American Pediatric Spine Anesthesiologists (NAPSA) Collaborative. This group included 34 anesthesiologists at 19 different institutions, each of whom has a Harms Study Group surgeon performing spine fusions at their hospital.

RESULTS

Thirty-one of 34 (91.2%) anesthesiologists completed the survey, with a missing response rate from 0% to 16.1% depending on the question. Most anesthesia practices (77.4%; 95% confidence interval [CI], 67.7-93.4) do not have patients come for a preoperative visit prior to the day of surgery. Intravenous induction was the preferred method (74.2%; 95% CI 61.3-89.9), with the majority utilizing two peripheral IVs (93.5%; 95% CI 90.3-100) and an arterial line (100%; 95% CI 88.8-100). Paralytic administration for intubation and/or exposure was divided (51.6% rocuronium/vecuronium, 45.2% no paralytic, and 3.2% succinylcholine) amongst respondents. While tranexamic acid was consistently utilized for reducing blood loss, dosing regimens varied. When faced with neuromonitoring signal issues, 67.7% employ a formal protocol. Most anesthesiologists (93.5%; 95% CI 78.6-99.2) extubate immediately postoperatively with patients admitted to an inpatient floor bed (77.4%; 95% CI 67.7-93.3).

CONCLUSION

Most anesthesiologists (87.1%; 95% CI 80.6-99.9) report the use of some form of an anesthesia-based protocol for AIS fusions, but our survey results show there is considerable variation in all aspects of perioperative care. Areas of agreement on management comprise the typical vascular access required, utilization of tranexamic acid, immediate extubation, and disposition to a floor bed. By recognizing the diversity of anesthetic care, we can develop areas of research and improve the perioperative management of AIS.

Deep versus moderate neuromuscular blockade during total hip arthroplasty to improve postoperative quality of recovery and immune function: protocol for a randomised controlled study

INTRODUCTION

There is accumulating evidence that deep neuromuscular blockade (NMB) improves intraoperative surgical conditions during laparoscopic surgery. Studies investigating the effects of deep NMB in open surgery are scarce. In theory, by limiting surgical damage through deeper muscle relaxation, postoperative inflammation and concomitant immune suppression can be reduced. Therefore, this study will investigate the effects of deep NMB during total hip arthroplasty, which demands a relatively large exposure of the hip joint through and in between muscles.

METHODS AND ANALYSIS

This study is a monocentre blinded randomised controlled trial in 100 patients undergoing total hip arthroplasty under general anaesthesia. Patients will be randomised in a 1:1 fashion to an intervention group of intraoperative deep NMB (a post-tetanic count of 1-2) or a control group receiving moderate NMB (a train-of-four count of 1-2). NMB will be achieved by continuous or bolus administration of rocuronium, respectively. The primary endpoint is the quality of recovery at postoperative day 1 measured by the Quality of Recovery-40 Questionnaire, analysed by Analysis of Variance. The secondary endpoint is postoperative innate immune function, measured by ex vivo production capacity of tumour necrosis factor and interleukin-1β on endotoxin stimulation of whole blood.

ETHICS AND DISSEMINATION

Ethical approval for this study was granted by the Medical Ethics Committee 'METC Oost-Nederland' (reference number 2022-15754). Informed consent will be obtained prior to study participation. Study results will be published in an international peer-reviewed journal.

TRIAL REGISTRATION NUMBERS

ClinicalTrials.gov Registry (NCT05562999) and EudraCT Registry (2022-002451-19).

Use of neuromuscular blockade for neck dissection and association with iatrogenic nerve injury

BACKGROUND

Cranial nerve injury is an uncommon but significant complication of neck dissection. We examined the association between the use of intraoperative neuromuscular blockade and iatrogenic cranial nerve injury during neck dissection.

METHODS

This was a single-center, retrospective, electronic health record review. Study inclusion criteria stipulated patients > 18 years who had ≥ 2 neck lymphatic levels dissected for malignancy under general anesthesia with a surgery date between 2008 - 2018. Use of neuromuscular blockade during neck dissection was the primary independent variable. This was defined as any use of rocuronium, cisatracurium, or vecuronium upon anesthesia induction without reversal with sugammadex prior to surgical incision. Univariate tests were used to compare variables between those patients with, and those without, iatrogenic cranial nerve injury. Multivariable logistic regression determined predictors of cranial nerve injury and was performed incorporating Firth's estimation given low prevalence of the primary outcome.

RESULTS

Our cohort consisted of 925 distinct neck dissections performed in 897 patients. Neuromuscular blockade was used during 285 (30.8%) neck dissections. Fourteen instances (1.5% of surgical cases) of nerve injury were identified. On univariate logistic regression, use of neuromuscular blockade was not associated with iatrogenic cranial nerve injury (OR: 1.73, 95% CI: 0.62 - 4.86, p = 0.30). There remained no significant association on multivariable logistic regression controlling for patient age, sex, weight, ASA class, paralytic dose, history of diabetes, stroke, coronary artery disease, carotid atherosclerosis, myocardial infarction, and cardiac arrythmia (OR: 1.87, 95% CI: 0.63 - 5.51, p = 0.26).

CONCLUSIONS

In this study, use of neuromuscular blockade intraoperatively during neck dissection was not associated with increased rates of iatrogenic cranial nerve injury. While this investigation provides early support for safe use of neuromuscular blockade during neck dissection, future investigation with greater power remains necessary.

Does deep neuromuscular blockade provide improved perioperative outcomes in adult patients? A systematic review and meta-analysis of randomized controlled trials

Deep neuromuscular blockade provides better surgical workspace conditions in laparoscopic surgery, but it is still not clear whether it improves perioperative outcomes, not to mention its role in other types of surgeries. We performed this systematic review and meta-analysis of randomized controlled trials to investigate whether deep neuromuscular blockade versus other more superficial levels of neuromuscular blockade provides improved perioperative outcomes in adult patients in all types of surgeries. Medline, Embase, Cochrane Central Register of Controlled Trials, and Google Scholar were searched from inception to June 25, 2022. Forty studies (3271 participants) were included. Deep neuromuscular blockade was associated with an increased rate of acceptable surgical condition (relative risk [RR]: 1.19, 95% confidence interval [CI]: [1.11, 1.27]), increased surgical condition score (MD: 0.52, 95% CI: [0.37, 0.67]), decreased rate of intraoperative movement (RR: 0.19, 95% CI: [0.10, 0.33]), fewer additional measures to improve the surgical condition (RR: 0.63, 95% CI: [0.43, 0.94]), and decreased pain score at 24 h (MD: -0.42, 95% CI: [-0.74, -0.10]). There was no significant difference in the intraoperative blood loss (MD: -22.80, 95% CI: [-48.83, 3.24]), duration of surgery (MD: -0.05, 95% CI: [-2.05, 1.95]), pain score at 48 h (MD: -0.49, 95% CI: [-1.03, 0.05]), or length of stay (MD: -0.05, 95% CI: [-0.19, 0.08]). These indicate that deep neuromuscular blockade improves surgical conditions and prevents intraoperative movement, and there is no sufficient evidence that deep neuromuscular blockade is associated with intraoperative blood loss, duration of surgery, complications, postoperative pain, and length of stay. More high-quality randomized controlled trials are needed, and more attention should be given to complications and the physiological mechanism behind deep neuromuscular blockade and postoperative outcomes.

Cortisol secretory patterns in deep and moderate neuromuscular blockades in laparoscopic surgery under total intravenous anesthesia: A prospective, single-blinded, randomized controlled trial

BACKGROUND

Neuroendocrine stress response induces physiological changes depending on the type of surgery and anesthesia. Although the optimal depth of neuromuscular blockade for reducing this response remains unknown, deep neuromuscular blockade is known to improve the surgical environment. Therefore, we hypothesized that a patient's stress response would be lower in surgical procedures under deep neuromuscular blockade than under moderate neuromuscular blockade.

METHODS

This prospective, randomized, single-blind study enrolled 72 patients who underwent laparoscopic gynecological surgery under general anesthesia and were assigned to group D (deep blockade: target train-of-four 0 and posttetanic count ≥ 1) or group M (moderate blockade: target train-of-four count 1-3). The primary endpoints were changing patterns in cortisol and adrenocorticotrophic hormone levels; the secondary endpoints were patient outcomes, such as hemodynamic variables, serum glucose level, postoperative pain in the postanesthesia care unit, and hospital stay.

RESULTS

The baseline characteristics were comparable between the 67 patients included in the 2 groups (34 in group M and 33 in group D). Cortisol and adrenocorticotrophic hormone levels increased perioperatively in both groups but without significant intergroup differences. Serum glucose level increased perioperatively and decreased postoperatively, but without a significant intergroup difference. Postoperative pain, fentanyl requirement in the postanesthesia care unit, and hospital stay were also comparable.

CONCLUSIONS

Compared with moderate neuromuscular blockade, deep neuromuscular blockade improved the surgical environment without significant intergroup differences in the hormonal stress response.

Hand or foot train-of-four tests and surgical site muscle relaxation assessed with multiple motor evoked potentials: A prospective observational study

BACKGROUND

Intra-operative muscle relaxation is often required in orthopaedic surgery and the hand train-of-four (TOF) test is usually used for its quantification. However, even though full muscle relaxation is claimed by anaesthesiologists based on a TOF count of zero, surgeons observe residual muscle activity.

OBJECTIVE

The aim of the study was to assess if hand or foot TOF adequately represents intra-operative muscle relaxation compared with multiple motor evoked potentials.

DESIGN

Prospective observational study.

SETTING

A single-centre study performed between February 2016 and December 2018 at the Balgrist University Hospital, Zurich, Switzerland.

PATIENTS

Twenty patients scheduled for elective lumbar spinal fusion were prospectively enrolled in this study after giving written informed consent.

INTERVENTIONS

To assess neuromuscular blockade (NMB) with the intermediate duration nondepolarising neuromuscular blocking agent rocuronium, hand TOF (adductor pollicis) and foot TOF (flexor hallucis brevis) monitoring, and muscle motor evoked potentials (MMEPs) from the upper and lower extremities were assessed prior to surgery under general anaesthesia. Following baseline measurements, muscle relaxation was performed with rocuronium until the spinal surgeon observed sufficient relaxation for surgical intervention. At this timepoint, NMB was assessed by TOF and MMEP.

MAIN OUTCOME MEASURES

The primary outcome was to determine the different effect of rocuronium on muscle relaxation comparing hand and foot TOF with the paraspinal musculature assessed by MMEP.

RESULTS

Hand TOF was more resistant to NMB and had a shorter recovery time than foot TOF. When comparing MMEPs, muscle relaxation occurred first in the hip abductors, and the paraspinal and deltoid muscles. The most resistant muscle to NMB was the abductor digiti minimi. Direct comparison showed that repetitive MMEPs simultaneously recorded from various muscles at the upper and lower extremities and from paraspinal muscles reflect muscle relaxation similar to TOF testing.

CONCLUSION

Hand TOF is superior to foot TOF in assessing muscle relaxation during spinal surgery. Hand TOF adequately represents the degree of muscle relaxation not only for the paraspinal muscles but also for all orthopaedic surgical sites where NMB is crucial for good surgical conditions.

TRIAL REGISTRATION

ClinicalTrials.gov (NCT03318718).

Comparison between the trapezius and adductor pollicis muscles as an acceleromyography monitoring site for moderate neuromuscular blockade during lumbar surgery

Acceleromyography at the adductor pollicis located in a distal part of the body may not reflect the degree of neuromuscular blockade (NMB) at the proximally located muscles manipulated during lumbar surgery. We investigated the usefulness and characteristics of acceleromyographic monitoring at the trapezius for providing moderate NMB during lumbar surgery. Fifty patients were randomized to maintain a train-of-four count 1–3 using acceleromyography at the adductor pollicis (group A; n = 25) or the trapezius (group T; n = 25). Total rocuronium dose administered intraoperatively [mean ± SD, 106.4 ± 31.3 vs. 74.1 ± 17.6 mg; P < 0.001] and surgical satisfaction (median [IQR], 7 [5–8] vs. 5 [4–5]; P < 0.001) were significantly higher in group T than group A. Lumbar retractor pressure (88.9 ± 12.0 vs. 98.0 ± 7.8 mmHg; P = 0.003) and lumbar muscle tone in group T were significantly lower than group A. Time to maximum block with an intubating dose was significantly shorter in group T than group A (44 [37–54] vs. 60 [55–65] sec; P < 0.001). Other outcomes were comparable. Acceleromyography at the trapezius muscle during lumbar surgery required a higher rocuronium dose for moderate NMB than the adductor pollicis muscle, thereby the consequent deeper NMB provided better surgical conditions. Trapezius as proximal muscle may better reflect surgical conditions of spine muscle.

A narrative review on the potential benefits and limitations of deep neuromuscular blockade

BACKGROUND

Neuromuscular blockade was shown to improve surgical conditions. However, the risk of residual neuromuscular blockade upon extubation prevents anaesthesiologists from maintaining complete paralysis. For this reason, deep NMB is still underused in anaesthesia. This review focused on answering six questions revolving around the use of deep NMB versus moderate NMB.

METHODS

This was a non-exhaustive narrative review based on 6 selected relevant questions: does deep NMB 1) improve surgical conditions? 2) reduce surgical complications? 3) facilitate a reduction in intraoperative pneumoperitoneum pressure (PnP)? 4) does a reduction in intraoperative PnP impact clinical outcomes? 5) does the combination of deep NMB and lower PnP improve respiratory parameters? 6) improve OR efficiency or readmission rates?

RESULTS

This review highlights some of the key studies that have demonstrated potential benefits of deep NMB, but it also included reports showing no benefit, highlighting that the evidence is not unequivocal. Deep NMB does in fact improve surgical conditions, but whether this improvement translates into improved clinical outcomes is far from concluded. Indeed, there is an increased risk or residual curarisation, especially if patients are not monitored and reversed appropriately. The most important benefit of deep NMB may be the prevention of unacceptable surgical working conditions. The other potential major benefits are the reduction in PnP and reduction in pain. Deep NMB must be used with appropriate monitoring.

CONCLUSION

Deep NMB was associated with an improvement in surgical conditions, reduction in PnP, pain, and complications; but further research is needed to definitively prove this relationship.

Assessment of the effects of sugammadex on coagulation profiles using thromboelastographic parameters

This study evaluated the effects of sugammadex at conventional doses of 2 and 4 mg/kg on the coagulation profile by analyzing thromboelastographic parameters and performing a traditional laboratory coagulation analysis. A total of 100 patients undergoing arthroscopic shoulder surgery were enrolled. The patients were randomly divided into the 2 mg and 4 mg groups. The laboratory coagulation test and thromboelastographic analysis were performed before and 15 min after administering sugammadex. Prothrombin time (PT) was significantly prolonged after sugammadex administration than before it in intragroup comparisons of the 2 mg group (12.8 ± 0.6 s vs. 13.6 ± 0.7 s, p < 0.001) and the 4 mg group (13.0 ± 0.5 s vs. 13.7 ± 0.5 s, p < 0.001). R time, derived from thromboelastography, was also significantly prolonged after sugammadex administration (4.7 ± 1.8 min vs. 5.8 ± 2.1 min, p = 0.005). In conclusion, the conventional doses of 2 or 4 mg/kg sugammadex prolonged PT. Sugammadex 4 mg/kg also prolonged R time, although the value was within the normal range. Therefore, physicians should be cautious with the higher sugammadex dose, particularly in patients with a high risk of bleeding because the higher dose was associated with less coagulation.

Trial registration: KCT0002133 (https://cris.nih.go.kr).